Did this start on the first time you started playing fifa14?
Usually fifa14 is not so demanding, playable.
Have you tried disk defragmentation, disk cleanup, disabling unnecessary start up applications, cleaning out temp folder?
You must run as administrator to make the change:
type temp in RUN PROGRAM, delete everything there in the folder
again
type %temp% in RUN, delete everything in the Folder
restart
You can try playing at lowest setting and reduce resolution, but it may be blurry.
thanks,